Recently, lighting devices which use organic EL (EL: Electroluminescence) elements as organic light emitting elements are under development for practical use. Conventionally, organic EL lighting panels have been known in each of which an organic EL element is connected to a power source by using a flexible film or a wiring member as a lead wire.
FIG. 9 shows an example of a conventional organic EL lighting panel. In the conventional organic EL lighting panel 100, an organic EL layer sandwiched between an anode and a cathode is disposed on a substrate. The anode is connected to an anode lead-out electrode 101, whereas the cathode is connected to a cathode lead-out electrode 102. A flexible cable is provided on the anode lead-out electrode 101 and the cathode lead-out electrode 102, which are electrically connected to terminals of the flexible cable (for example, refer to Patent Document 1).
As described above, in the conventional organic EL lighting panel, a power input terminal is provided on each of any of four edges of a quadrilateral panel or all of the four edges as in the case of a display panel. A lead wire is led out from each power input terminal by use of a flexible cable. Patent Document 1: Japanese Patent Application Publication No. 2007-066709